1. Field of the Invention
The present invention relates to the field of object referential integrity and more particularly to maintaining object referential integrity for object references for abstract objects.
2. Description of the Related Art
Objects within the context of network computing refer to resources which can be accessed and utilized within a host computing device. Generally, objects can range from documents, such as Web pages, to image files and even programmatic logic. Objects often are referenced by name and include a location within memory or within a file system, either explicitly or implicitly. In the explicit circumstance, a network location can be specified—which also can be limited to a single host computing device not communicatively connected to other computing devices—and a path to the object also can be specified, for instance a file path. In the implicit circumstance, the network location, file system path, or both can be assumed by the context of the reference and only the identifying name of the referenced object is specified.
Object references often are encountered in the Internet and Intranet context where markup language documents reference one or more objects from within the document. Generally, objects can be referenced by way of a network address such as a URL. The format for addressing an object by a uniform resource locator (URL) can include                protocol://[network-location]:[port]/[file-system-location]/[object-name]where occasionally any of the port, file system location, and protocol can be presumed. Addressing an object by network address has proven to be highly effective when used in conjunction with concrete and seldom changing objects.        
In the modern world of distributed computing, however, it is more often the case where an object changes either in respect to network location or file system location. To address the problem of oft-changing object references, methodologies have been proposed to preserve referential integrity of objects within Web sites. For example, see United States Patent Application Publication No. US 2004/0024848 A1 by Smith et al. Common solutions for referential integrity rely upon database tables listing referenced objects with valid locations. In this way, an accurate and valid reference for an object can be acquired through a quick lookup in the database.
As before, though, object references can be adequately managed using the database approach only so long as the objects are concrete in nature. Abstract objects, however, often do not enjoy directly addressable concrete properties such as an identifier and location. Object relationships, for example, nested object hierarchies, are abstract in nature. For instance, one referenced object can depend on the presence of one or more other object references and so forth.
To address object referential integrity for abstract objects, many have reverted to a proprietary object reference format which incorporates the object hierarchy in a single network address. For anything more than a single dependency, though, the formatting can become clunky and the solution, in its entirety, lacks extensibility. Also, proprietary formatting can fail where an address for a dependent object in the hierarchy changes. In the latter circumstance, the object hierarchy is not updateable and the logic processing the proprietary addressing must know to change each reference to the dependent object.